import 'dart:convert';

main() {
  String data = '{"id":"1fe7849e-95e2-4fba-808c-4b9cede72cea","fileName":"LL6TC9VJULV5W0WB8Z.txt","startTime":"2019-3-23 08:00:00","endTime":"2019-3-23 08:10:10","status":"END"}';

  List<Map<String, dynamic>> listOfColumns = [
    {"id":"ecd461b8-33fb-43e4-a2ce-d2f38da68ea6","fileName":"S12FHYFNB7WRFA2UI2.txt","startTime":"2019-3-23 08:00:00","endTime":"2019-3-23 08:10:10","status":"END"},
    {"id":"6e3043cf-20f3-4a4b-a608-cfdfad164c1f","fileName":"4GQ9PW6J3X6QZIWAPB.txt","startTime":"2019-3-23 08:00:00","endTime":"2019-3-23 08:10:10","status":"END"}
  ];

  listOfColumns.add(json.decode(data));

  print(listOfColumns);
}